Color printer system for histological specimen slides and cassettes

ABSTRACT

A color printer for histological specimen containers such as slides and cassettes includes a specimen container receiving structure to receive histological specimen containers having a print zone, an ink receiving structure to receive a multi-colored ink source, a printhead, a drive mechanism to drive specimen containers received by the container receiving structure with respect to the print head, and a control system. The control system is responsive to specimen data representative of histological specimens and controls the drive mechanism and the printhead, including causing the print head to transfer multiple colors of ink from the ink source and print specimen information in color on the print zones of specimen containers. In one embodiment of the invention the specimen data includes color data representative of a color that identifies specimen information, and the control system causes the printhead to print the specimen information in color as a function of the color data. In another embodiment the control system causes the printhead to print specimen information in the form of a color bar as a function of the color data, and to print specimen information in the form of text and a bar code in black.

BACKGROUND

The present invention relates to color printers and printing methods forhistological specimen containers such as slides and cassettes.

Printers for printing information on containers such as slides andcassettes used to process histological specimens (e.g., tissue biopsies)are generally known and commercially available. These printers printinformation in the form of text and bar codes in monochrome (i.e., usingblack ink). Slides and cassettes having different color backgrounds aresometimes used in the printers, and the color of the slides andcassettes can be selected to represent information such as the type oftissue on the container. During printing applications of these types,slides and cassettes of different colors can be switched in and out ofthe printer. Some printers are configured with several slide andcassette inputs, and supplies of slides and cassettes having differentcolors can be loaded into these printers. Operators of printers of thesetypes need to stock slides and cassettes having the different colorbackgrounds.

There remains a continuing need for improved printers for histologicalsample containers. In particular, there is a need for printers andmethods that are efficient to operate and perform, and that enableinformation to be accurately printed on the containers.

SUMMARY

The present invention is a color printing system for histologicalspecimen containers. The system is efficient to operate and capable ofaccurately printing specimen information in color on containers such asslides and cassettes.

One embodiment of the invention is a histological specimen containerprinter that includes a specimen container receiving structure toreceive histological specimen containers having a print zone, an inkreceiving structure to receive a multi-colored ink source, a print head,a drive mechanism to drive specimen containers received by the containerreceiving structure with respect to the print head, and a controlsystem. The control system is responsive to specimen data representativeof histological specimens to control the drive mechanism and the printhead, including causing the print head to transfer multiple colors ofink from the ink source and print specimen information in color on theprint zones of specimen containers. In some embodiments of the inventionthe specimen data includes color data representative of a color thatidentifies specimen information, and the control system causes the printhead to print the specimen information in color as a function of thecolor data.

Another embodiment of the invention is a method for operating a colorprinter to print specimen information on histological specimencontainers. The method includes actuating a color printer as a functionof specimen data representative of specimen information to applymultiple colors of ink and print the specimen information in color onthe print zones of the specimen containers. In some embodiments thespecimen data includes color data representative of colors that identifyspecimen information, and actuating the color printer includes printingthe specimen information in color as a function of color data. In otherembodiments actuating the color printer includes printing specimeninformation in the form of color bars as a function of the color data.In still other embodiments actuating the color printer includes printingspecimen information in the form of bar codes. In yet other embodimentsactuating the color printer includes printing specimen information inthe form of text as a function of the color data.

Another embodiment of the invention is a histological sample containerprinter that includes a sample container receiving structure to receivehistological sample containers having a frosted or white print zone, athermal print head, a sample container drive mechanism to drive thesample containers from the sample container receiving structure withrespect to the print head, an ink receiving structure to receive amulti-color thermal print ribbon having a set of primary (e.g., yellow,magenta and cyan) and optionally black ink color blocks spaced along alength of the ribbon, a print ribbon drive mechanism to drive the printribbon with respect to the print head, a data port for receiving sampledata representative of histological sample information, and a controlsystem coupled to the print head, sample container drive mechanism,print ribbon drive mechanism and data port. The control system operatesto control the sample container drive mechanism to move the print zoneof sample containers back and forth with respect to the print head, tocontrol the print ribbon drive mechanism to advance the print ribbon andlocate the color blocks with respect to the print head, to control theprint head as a function of the sample data and cause the print head toheat and transfer ink from one or more of the yellow, magenta and cyanink blocks and print a color block representative of the sampleinformation at a first location on the print zone of the samplecontainers, to control the print head as a function of the sample dataand cause the print head to heat and transfer ink from the black or aprimary color ink block and print a bar code representative of thesample information at a second location on the print zone of the samplecontainers, wherein the second location is spaced from the firstlocation, and to control the print head as a function of the sample dataand cause the print head to heat and transfer ink from the black or aprimary color ink block and print text representative of the sampleinformation at a third location on the print zone of the samplecontainers, wherein the third location is spaced from the first andsecond locations. In some embodiments the data port receives sample datarepresentative of histological sample information including sample typeinformation, and the control system causes the print head to print acolor block, bar code and/or text in a color representative of thesample information.

Another embodiment of the invention is a method for printing sampleinformation on a histological sample container. The method includesreceiving data representative of histological sample information,receiving a histological sample container having a print zone with aflat, thermal ink-receptive surface, receiving a multi-color thermalprint ribbon having primary (e.g., yellow, magenta and cyan) andoptionally black ink color blocks spaced along a length of the ribbon,advancing the print ribbon to a stationary position with respect to athermal print head to locate a first of the yellow, magenta and cyan inkcolor blocks with respect to the print head, driving the samplecontainer to move the print zone by the stationary print head and printribbon, actuating the print head as a function of the data while drivingthe sample container to heat and transfer ink from the one of theyellow, magenta and cyan ink blocks and print a color bar at a firstlocation on the sample container print zone, optionally repeating thesteps of advancing the print ribbon, driving the sample container andactuating the print head to transfer ink from a second of the yellow,magenta and cyan ink blocks and print the color bar at the firstlocation on the sample container print zone, optionally repeating thesteps of advancing the print ribbon, driving the sample container andactuating the print head to transfer ink from a third of the yellow,magenta and cyan ink blocks and print the color bar at the firstlocation on the sample container print zone, advancing the print ribbonto a stationary position with respect to the thermal print head tolocate the black ink or a primary color ink block with respect to theprint head, driving the sample container to move the print zone by thestationary print head and print ribbon, and actuating the print head asa function of the data to heat and transfer ink from the color block andprint a bar code at a second location on the sample container printzone, wherein the second location is spaced from the first location. Insome embodiments receiving a slide includes receiving a slide having aprint zone with a white or frosted finish. In still other embodimentsactuating the print head to print ink from the black or primary colorink block further includes actuating the print head as a function of thedata to print text at a third location on the sample container printzone, wherein the third location is spaced from the first and secondlocations.

Yet another embodiment of the invention is a method for operating athermal printer to print sample information on a histological samplecontainer. The method includes receiving at the printer datarepresentative of histological sample information, loading into theprinter a histological sample container having a print zone with a flat,thermal ink-receptive surface, loading into the printer a multi-colorthermal print ribbon having primary color (e.g., yellow, magenta andcyan) and optionally black ink color blocks spaced along a length of theribbon, causing the print ribbon to advance to a stationary positionwith respect to a thermal print head and locate a first of the yellow,magenta and cyan ink color blocks with respect to the print head,causing the sample container to be driven to move the print zone by thestationary print head and print ribbon, causing the print head to beactuated as a function of the data while the sample container is beingdriven to heat and transfer ink from the one of the yellow, magenta andcyan ink blocks and print a color bar at a first location on the samplecontainer print zone, optionally repeating the steps of causing theprint ribbon to advance, causing the sample container to be driven andcausing the print head to be actuated to transfer ink from a second ofthe yellow, magenta and cyan ink blocks and print the color bar at thefirst location on the sample container print zone, optionally repeatingthe steps of causing the print ribbon to advance, causing the samplecontainer to be driven and causing the print head to be actuated totransfer ink from a third of the yellow, magenta and cyan ink blocks andprint the color bar at the first location on the sample container printzone, causing the print ribbon to advance to a stationary position withrespect to the thermal print head and locate the black or a primarycolor ink block with respect to the print head, causing the samplecontainer to be driven to move the print zone by the stationary printhead and print ribbon, and causing the print head to be actuated as afunction of the data to heat and transfer ink from the ink block andprint a bar code at a second location on the sample container printzone, wherein the second location is spaced from the first location.

Another embodiment of the invention is a histological sample container.The container comprises a member having a sample-receiving region and aprint zone with a flat, ink-receptive surface, a color bar formed byoverlaying layers of primary (e.g., yellow, magenta and cyan) thermaltransfer or other types of ink bonded to the base at a first location onthe print zone, a bar code formed by a layer of black or color thermaltransfer or other type of ink bonded to the base at a second location onthe print zone, wherein the second location is spaced from the firstlocation, and text formed by a layer of black thermal transfer or othertype of ink bonded to the base at a third location on the print zone,wherein the third location is spaced from the first and secondlocations.

Another embodiment of the invention is a set of consumable componentsfor a histological sample container printer. The set includes amulti-color thermal print ribbon or other carrier having a plurality ofprimary color (e.g., yellow, magenta and cyan) and optionally black ink(e.g., color blocks spaced along a length of the ribbon), andhistological sample containers, each container having a sample-receivingregion and a print zone with a sufficiently flat surface to enablethermal or other transfer and bonding of the yellow, magenta, cyanand/or black ink from the print ribbon or other carrier.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top sectional view of a histological specimen slide printingsystem in accordance with one embodiment of the invention, taken on line1-1 in FIG. 2

FIG. 2 is a sectional view of the slide printing system shown in FIG. 1,taken on line 2-2 in FIG. 1.

FIG. 3 is a top plan view of a slide printed in accordance with oneembodiment of the invention by the printing system shown in FIG. 1.

FIG. 4 is a block diagram of an operational sequence that can be usedwith the printing system shown in FIG. 1.

FIG. 5 is a side view of the printing system shown in FIG. 1, with acover carrying the printer in an open position.

FIG. 6 is a front end view of the printing system shown in FIG. 1, withthe slide cassette removed.

FIG. 7 is an isometric view of the slide cassette shown in FIG. 1

FIG. 8 is an isometric view of a print ribbon that can be used in theprinting system shown in FIG. 1.

FIG. 9 is an isometric view of the printing system shown in FIG. 1 withthe cover open.

FIG. 10 is an isometric view of a molded tissue cassette in accordancewith one embodiment of the invention, shown with a lid attached to abase in an open position.

FIG. 11 is a sectional view of the cassette taken along line 11-11 inFIG. 10, showing the lid in a partially closed position during theinitial closing and before fracturing a hinge member.

FIG. 12 is a sectional view of the cassette taken along line 11-11 inFIG. 10, showing the lid moved further toward a closed position relativeto a cassette base.

FIG. 13 is a sectional view of the cassette taken long line 13-13 inFIG. 10, showing the lid in a partially closed position.

FIG. 14 is a sectional view of the cassette taken along line 11-11 inFIG. 10, showing the lid in a fully closed position and illustrating thefracturing of the hinge caused by the initial closing.

FIG. 15 is a front isometric view of a molded tissue cassette inaccordance with another embodiment of the invention showing aprint-receptive, information display panel.

FIG. 16 is an isometric view from a rear side of the cassette shown inFIG. 15.

FIG. 17 is an isometric view from the bottom of the cassette shown inFIG. 15, showing support ribs or gussets for supporting the displaypanel on which information is to be printed.

FIG. 18 is a detailed sectional view of the cassette taken along line18-18 in FIG. 16.

FIG. 19 is a detailed sectional view of the cassette taken along line19-19 in FIG. 18

FIG. 20 is an isometric view of a cassette printer in accordance withone embodiment of the invention.

FIG. 21 is an isometric view of the inside of the lid of the printershown in FIG. 20, showing the printhead assembly.

FIG. 22 is an isometric view of the printer shown in FIG. 20, with thelid removed and showing the cassette index assembly and print ribbonreceiving structure.

FIG. 23 is another isometric view of the inside of the lid of theprinter shown in FIG. 20, showing the printhead assembly.

FIG. 24 is a cross sectional view of the lid and printhead assembly.

FIG. 25 is an isometric view of the hopper shown in FIG. 20, showing thefront side.

FIG. 26 is an isometric view of the hopper shown in FIG. 20, showing theback side.

FIG. 27 is an isometric view of the printer shown in FIG. 20, with thelid removed and showing the cassette index assembly and the latches forengaging the hopper.

FIG. 28 is a detailed top plan view of the back of the printer shown inFIG. 20, showing the opening in the cover and the hopper and cassetteloading rod.

FIG. 29 is a side plan view of the cassette loading rod shown in FIG.20.

FIG. 30 is an isometric view of the loading rod shown in FIG. 29,showing the front side.

FIG. 31 is an isometric view of the loading rod shown in FIG. 29,showing the back side.

FIG. 32 is a detailed side view of the inside of the printer shown inFIG. 20, showing the loading rod being inserted into the hopper whileretaining the cassettes.

FIG. 33 is a detailed side view of the inside of the printer shown inFIG. 20, showing the loading rod latched into the printer and releasingthe cassettes.

FIG. 34 is an isometric view of the cassette index assembly shown inFIG. 22, with a cassette in a position after picking.

FIG. 35 is an isometric view of the cassette index assembly shown inFIG. 34, with the cassette in a position after printing.

FIG. 36 is an isometric view of the cassette index assembly shown inFIG. 34, with the cassette in a position being reset.

FIG. 37 is an isometric view of the cassette index assembly shown inFIG. 34, with the cassette in a position after being reset.

FIG. 38 is an isometric view of the cassette index assembly shown inFIG. 34, showing a side opposite the side shown in FIG. 34.

FIG. 39 is an isometric view of the printer shown in FIG. 20, with thelid removed and showing the cassette index assembly and print ribbonreceiving structure.

FIG. 40 is an isometric view of the printer shown in FIG. 20, with thelid removed and showing the print ribbon receiving structure.

FIG. 41 is an isometric view of the printer shown in FIG. 20, with thelid removed and showing the print ribbon receiving structure.

FIG. 42 is an isometric view of a print ribbon that can be used in theprinter shown in FIG. 20.

FIG. 43 is a front end plan view of the printer shown in FIG. 20, withthe lid removed.

FIG. 44 is a block diagram of the electrical subsystem of the printershown in FIG. 20.

FIG. 45 is a detailed isometric view of an output tray and stop inaccordance with another embodiment of the printer shown in FIG. 20.

FIGS. 46 and 47 are side views of the output tray and stop shown in FIG.45, with the stop shown in up and down positions, respectively.

FIGS. 48-51 are top plan, end plan, side plan and isometric views,respectively of the base of the output tray shown in FIGS. 45-47.

FIG. 52 is an isometric view of the stop of the output tray shown inFIGS. 45-47.

FIG. 53 is a sectional view of the output tray stop, taken along line53-53 in FIG. 52.

DETAILED DESCRIPTION Overview

Color histological specimen container printers in accordance with theinvention are described below in connection with FIGS. 1-53. Oneembodiment of the printer invention is a color slide printer 10described in connection with FIGS. 1-9. Slide 100, a specimen containerin accordance with one embodiment of the invention that can, forexample, be color printed using the slide printer 10, is described inconnection with FIG. 3. Another embodiment of the invention is a colorcassette printer 200 described in connection with FIGS. 20-53. Cassette500, a specimen container in accordance with the invention that can, forexample, be color printed using the cassette printer 200, is describedin connection with FIGS. 10-14. Yet another embodiment of a specimencontainer in accordance with the invention, cassette 600, can also becolor printed using the cassette printer 200 and is described inconnection with FIGS. 15-19.

Color Slide Printer 10

A color slide printing system 10 in accordance with one embodiment ofthe invention can be described generally with reference to FIGS. 1-5. Asshown, slide printing system 10 includes an outer cabinet 12 in whichcomponents are mounted, and the cabinet includes a cross support wall 14extending between and suitably supported on side walls 16. The sidewalls 16 are used for rotatably supporting various drive rollers andother components. A medical slide cartridge indicated generally at 18(also sometimes referred to as a cassette or magazine) is a rectangularcontainer that holds a plurality of individual slides 100. The slides100 can be of a desired type, and can be clear or opaque and they willhave a finish on at least portions of one surface that will accept inkfrom a thermal printer that has a multi-colored ribbon. A frosted finishin the area to be printed is suitable.

The cartridge 18 is a self-contained unit that can be loaded with slides100 from the bottom or can have a suitable access cover, and it can beslid in and out of the outer printer housing 12 through a providedopening, and between side guides (FIG. 1) and rested on the support wall14. As can be seen, the cartridge size is selected to support a numberof slides 100 in a stack (usually 100), and the bottom wall 22 of thecartridge 18 has a feed opening 24 defined therein formed, byterminating the bottom wall 22 so it is spaced from an inner or infeedend wall 25. The end wall 25 is terminated with a bottom edge 26 spacedslightly above the top plane of the bottom wall 22, so that when acartridge 18 is positioned in the print housing, as shown in FIG. 2, aninput feed roller 28 will support the bottommost slide 100 (the roller28 projects above wall 14), and hold the end of the slide position sothat the bottom slide will clear the bottom edge 26. The input feedroller 28 will withdraw the bottom slide 100 through the opening 24 whenthe feed roller is powered.

The input feed roller 28 is driven by a suitable motor 32 from a centralcontrol system 34 which comprises a microcontroller that can beprogrammed for sequencing the various components being controlled in adesired manner and which coordinates the printing on the slide 100 foridentification.

Provided slide guides 35 will support a slide 100 after it is moved bythe input feed roller 28 underneath the wall edge 26, and the input feedroller 28 will provide an impetus to move the slide along the guides 35until it is grasped by drive rollers indicated at 38 and 40. At leastone of the drive rollers, for example drive roller 40 is driven by amotor 42 that is also controlled by the control system 34. The slide 100being fed is grasped between the drive rollers 38 and 40 and is movedacross a slide position sensor 37 onto a printer printhead platen roller46 that is driven by a motor 48 from control system 34. The slideposition sensor 37 provides a position signal to control system 34 sothe drive rollers 38 and 40 are driven to properly position the slide100 relative to the printhead.

Printhead platen roller 46 is independently mounted between the sidewalls 16 of the housing, and above the platen roller there is a thermalprinter indicated at 50 that includes a thermal printhead 52 that willprint on an upper surface of a slide, for example, the slide 100A shownin FIG. 2 between the drive rollers 70 and 72 and supported on theprinthead platen roller 46. The printer 50 is carried on a cover 49 thatcan be opened as shown in FIG. 5, and the printer is supported on thecover 49 for movement toward and away from printhead platen roller 46when the cover 49 is closed. A lever 51 is pivoted at a pivot 51A andhas an end finger 51B that engages a crossbar on the printer 50 frame. Acam 53 is positioned to act on a cam follower 51C on the lever 51 tolift the printer and printhead when the cam is rotated by a motor 55.The motor 55 is controlled by control system 34.

The slide 100A is moved beneath a multi-color thermal print ribbonindicated at 54 which is fed from a ribbon supply roller 56 mountedbetween the side walls 16 and which passes under the printhead 52. Theprint ribbon supply roller is driven by a suitable motor 59. The ribbon54 is a known ribbon with blocks of heat transferable color along itslength in a known sequence, namely yellow (Y), magenta (M), cyan (C) andblack (K). The ribbon 54 passes across a print ribbon sensor 58 thatprovides signals indicating the start of each block of color on theribbon to the control system 34. Guide rollers 57 are also provided forthe ribbon 54 between the supply roller 56 and the printhead 52. Theribbon 54, after it has been used for printing onto the slide 100A, istaken up on a print ribbon take up roller 62, that can be driven with asuitable motor 64 controlled by the control system 34.

Prior to printing, the printhead 52 is raised by operating cam 53 tolift the printer and the slide 100A will be moved forwardly toward apair of drive rollers 70 and 72 again, at least one of which is driven,for example by schematically illustrated motor 74 coordinated with thecontrol system 34. It should be noted that while individual drive motorsfor the feed rollers and platen roller are shown for illustrationpurposes, the rollers that are timed or coordinated can be driven by onemotor and a gear train shown generally at 71 in FIG. 5.

As the slide 100A is printed (as shown in FIG. 1), it should beunderstood that it will be moved back and forth by drive rollers 70 and72 and platen roller 46 under control of the control system 34. Printingoccurs adjacent one end of the slide as shown in FIG. 3 so the driverollers 70 and 72 are usable for moving the slide 100A while it is beingprinted on. The printhead 52 has enough lateral width so that theprinting can take place along the lateral width of the slide wide enoughto include the information necessary. The printhead 52 is lifted whenneeded for moving the slide 100A to reposition it.

After the slide 100A has been printed by printing a colored bar 90 (SeeFIG. 3), a bar code 92 and identification text 94, the slide is driventhrough the drive rollers 70 and 72 under the power of motor 74, and itis dropped into a storage facility. In this form, the printed slide isdropped onto a conveyor belt 76 that is mounted over first and secondend rollers 78 and 80. The end of the conveyor supported by roller 80 islocated back underneath the slide cartridge 18. The roller 80 can bedriven by a suitable motor 82 controlled by the control system 34, orcan be driven by the gear train 71.

The printed slides carried on the upper length of the conveyor belt 76will be dropped into a slide output tray or bin 84 that is mounted in asuitable manner at an incline underneath the slide holder cartridge 18.The slides that have been printed have been shown at 86 in a stack.

The cartridges 18 could be loaded with different types of slides ifdesired, for example, if a party wanted to use colored slides with amonochrome ribbon instead of color ribbon with white or clear slides,the slide cartridge allows the user to easily switch slide colorswithout handling the slides. Multiple cartridges could be used to storemultiple colors, which can be easily identified and switched whilekeeping them dust and fingerprint free.

In use, the administrator of the company that was using the slideidentification system of the present disclosure would set up somevariables for their system, for example, an automated color selectionwhere a particular color identifies a particular tissue. For example,liver tissue could be blue; kidney tissue could be green; heart tissuecould be red; lung tissue could be black and so on. The data input 33into the software of the control system 34 can be manually input or readfrom another source, and used to identify the type of slide that was tobe printed, and also for each particular slide the data would include inthe software the text that was to be printed and the identification barcode that is to be printed on the slide. Then, the software wouldautomatically select the slide identification color, based on the inputdata and the printhead would be operated to print the strip oridentifying block 90 on the one end portion of the slide such as thatshown in FIG. 3, and then the data relating to the specimen that wouldbe placed on the slide is printed as text 94 and bar code 92 foridentification. This can be done in a black color, so the slideinformation would be in two colors.

The thermal printer permits the color identifier bar or block 90 to beprinted easily in a selected color and then the information about thetissue sample on the slide can be printed in a different color, such asblack.

The ability to print the identifying color for the type of tissue thatwould be placed on the slide at the same time that the bar code isplaced on eliminates errors in identifying the color code to be used.

FIG. 3 illustrates a typical slide 100A after printing and mounting aspecimen thereon having the identifying color bar 90 shown in oneportion of the slide and the printed data 94, including a bar code 92that is printed in black and adjacent to the color bar and with aspecimen 96 that is keyed to the information on the slide mounted on theslide. The specimen 96 can be covered by a slip cover 98 and retained onthe slide in a known manner where desired.

FIG. 6 is a front end view of one embodiment of the the printing system10, with slide cartridge 18 removed from the cabinet 12 to show thecartridge receiving area 31. As shown, an electrical contact 23 ismounted on a wall 27 at the back of the cartridge receiving area 31. Theelectrical contact 23 is coupled to the control system 34. FIG. 7 is anillustration of a slide cartridge 18 with its access cover 19 open andshowing the slides 100 stacked therein. The illustrated embodiment ofthe cartridge 18 has a memory chip 43 mounted to its back wall. Thememory chip 43 is mounted to the cartridge 18 at a position that willenable the memory chip to electrically contact or otherwise be coupledfor data transfer with the electrical contact 23 on the printing system10 when the cartridge is inserted into the enclosure 12.

FIG. 8 is an illustration of a print ribbon assembly 61 that can be usedwith the slide printing system 10. As shown, the print ribbon assembly61 includes supply spool 63, take-up spool 65, and multi-color thermalink ribbon 54. The composition of thermal ink ribbons such as 54 isgenerally known. As described above, in one embodiment of the inventionthe ribbon 54 has a plurality of primary color ink blocks (e.g., yellow,magenta and cyan) and black ink blocks (not separately shown in FIG. 8)spaced in repeating sequences along its length. Rotatably mounted to thesupply spool 63 is a hub 67. A print ribbon memory chip 69 is mounted tothe hub 67 in this embodiment. FIG. 9 illustrates an embodiment of theprinting system 10 where the print ribbon supply hub 45 includes anelectrical contact 73 configured for electrical coupling to the memorychip 69 on the supply spool 63. The print ribbon assembly 61 is loadedonto the print ribbon receiving structure by mounting the supply spool63 to the supply hub 45, and mounting the take-up spool 65 to the takeup hub 47. The memory chip 69 on the supply spool 63 is electricallycoupled to the ribbon supply chip contact 73 when the supply spool 63 ismounted to the supply hub 45.

When the printing system 10 is switched ON the control system 34 canaccess information on the slide cassette memory chip 43 throughelectrical contact 33, and can access information on the ribbon supplymemory chip 69 through the electrical contact 73. Information stored onthe slide cassette memory chip 43 can include, for example, one or moreof slide type and the number of slides remaining in the cartridge 18.Similarly, information stored on the ribbon supply memory chip 69 caninclude ribbon type, the number of images remaining on the ribbon 54,production date and/or batch no. Other or additional types ofinformation can be stored on memory chips 43 and 69 in otherembodiments. Information on the memory chips 43 and 69 is used tocontrol the operation of printing system 10, and can be updated afterprint operations. For example, if the information on memory chips 43 or69 indicates that the supply of slides or ribbon is exhausted, thecontrol system 34 will not execute a requested print operation.Information stored on memory chips 43 or 69 representative of the numberof remaining slides and the number of images remaining on the ribbon 54can be updated following each print operation. If the types of slidesand print ribbon loaded into the printer are not compatible, theunsuitable combination can be identified and an informational messagecan be provided and/or printing can be discontinued to reduce errors.

In summary, the printer will have an input area that holds unprintedslides with a frosted area (typically white) used to record data. Theslides will be contained in a cartridge that will hold slides. An inputfeed roller will drive one slide out of the cartridge and move ittowards the printhead. A slide position sensor will locate the slide asit exits the cartridge and allow the controls to control the driverollers to precisely locate the printable area of the slide under theprinthead. The ribbon drive motor will then advance the multiple colorpanel ribbon until the leading edge of the first color panel of thesequence (typically yellow in a YMCK ribbon) is positioned under theprinthead as well. A ribbon sensor detects the transition between thecolor blocks on the ribbon and allows the control system to indicate tothe printer the location of each color block on the ribbon relative tothe printhead. When both the slide and the ribbon are in the properlocation, the printhead will be lowered and the drive rollers and theplaten roller will advance the slide as the first color panel isprinted. The printhead will be raised by a cam, the slide will back upuntil the leading edge is under the printhead and the color ribbon willbe advanced until the leading edge of the next panel is under theprinthead. Then the printhead will lower and the drive rollers willadvance the slide as the second color panel on ribbon is printed. Thisprocess will repeat for the remaining color panels. Once all of thecolor panels have completed printing, the drive rollers will advance theslide until it exits the printhead area and is transferred to a conveyorbelt which will move the slide to the output hopper located on the frontof the machine directly under the input cartridge.

The data for the slide can either be manually entered at a computer or ahistology tissue cassette with a bar code containing all pertinentinformation that can be scanned to obtain the required data to bereprinted on slides.

The sequence of operations in FIG. 4 shows the steps in the processusing the colored ribbon for printing.

The invention provides for a printing system that includes a cartridgefor holding a number of medical slides or histological slides on whichtissue samples or other medical samples are to be placed, and which willbe provided to a printer that will print in color on the slide forfurther identification of the class of tissue or sample that is to beplaced onto the slide, as well as printing information about thespecimen on the slide. This includes printing a bar code and/or textcontaining the data necessary for use of the slide, such as case number,patient name, year, issue class, priority rating etc. The slides will beprepared with an ink receptive surface, such as frosting the areas wherethere will be printing.

The slides are loadable in a cartridge so that they can be handledwithout getting fingerprints on the slides themselves, and multiplecartridges can be used, each to store slides for a differentclassification of specimens to be mounted on slides. The cartridges thencan be easily identified as to the class of the specimen and thecartridge switched while keeping the slides dust and fingerprint-free.

The printer utilizes a series of drive rollers for carrying slidesindividually from the cartridge, and feeding them into a print stationthat includes a platen roller that supports the slide for printing and aprinthead that prints the information on a surface opposite from theplaten roller. The slide can be moved back and forth by suitable driverollers for multi-color printing, or black and white printing, and whenthe information has been printed into the slide, the slide is removedfrom the print station (the printhead is lifted away from the slide asit is moved for printing and out of the print station) and then theslide is transferred to an output bin. The finished slide transferdevice includes a conveyor belt that will receive the slides andtransport the printed slides to a bin. Other types of storage can beprovided as well.

The printhead is controlled by suitable software that will print anidentifying color mark, in a bar or strip form onto the slide, and thenthe data that is required, including a text and the bar code foridentification is printed on the slide, and this is generally done inblack printing. A control system is used for coordinating variousmovements with the printing operations, including controlling thelifting and lowering of the printhead, the motors for the slide driverollers, and the platen roller for multiple pass printing to print thedesired identification information on the slide.

Although described in connection with embodiments of a thermal printer,those of skill in the art will recognize that the invention can beimplemented in still other embodiments. For example, other embodimentsof the invention can be implemented in inkjet, laser or other printers.One or more single color ink ribbons can be used instead of the multiplecolor panel ribbon. The printhead can be a separate printhead for eachink ribbon instead of the single printhead shown in the illustratedembodiment. Any and all of the fields of information on the slides canbe printed in any desired color, and the printed color can be selectedto represent information such as tissue type and source (e.g., the textand/or bar code can also be printed in color). Printing can also be donein one, two, three or more colors on each slide, with sequentiallyprinted slides having the same or different printed colors. The printercan also be used with other slides, such as slides having a coloredprinting area.

Cassette 500

A histological tissue carrying cassette in accordance with oneembodiment of the invention and indicated at 500 can be described withreference to FIGS. 10-14. As shown, cassette 500 includes a base 511having a bottom wall 512 that has a number of openings 514 formedtherein and which provide for drainage. The bottom wall 512 issurrounded by four upright side walls when a rectangular configurationis utilized, including a pair of side walls 516, a rear wall 518 and afront wall 520.

A tissue sample holding compartment 522 is thus formed by the side walls516, rear wall 518 and front wall 520. The rear wall 518 has a guideopening 526, and there is generally a U-shaped wall 524 formed on theinterior of the compartment to shield the opening 526 in the rear wall.Additionally, a partial offset wall portion 527 is provided in alignmentwith a slot 528 in one of the side walls 516, as shown. The slot 528provides a structure of feeding the cassettes 500 from a stack into aprocessing station. In the embodiment of the cassette printer 200described below, for example, the slot 528 is configured to be slidablyengaged by a cassette loading rod that can hold a stack of the cassettesand be releasably inserted into the printer.

A lid 530 is molded as a unit with the base 511 and after molding isintegrally attached to an upper edge of the rear wall 518 with a thin(reduced thickness of material) frangible hinge 532 formed duringmolding. The frangible hinge 532 extends across the upper edge of therear wall 518, except in locations where there are recesses for guideprojections or lugs that will be explained. The lid 530 has a rim 534that will fit inside the upright walls 516, 520 and 518 of the base 511,and there is a flange 536 that surrounds the rim 534 and will rest onthe top edges of the respective upright walls of the base. One side ofthe frangible hinge 532 is molded to the upper edge of wall 518 and theother side of the frangible hinge is molded to the mating or adjacentedge of the lid 530. The frangible hinge has a defined, selected lengthbetween the edge of wall 518 and the mating edge of the lid 530.

The lid 530 is provided with perforations or slots 538, which correspondgenerally in alignment with the slots 514 in the bottom wall 512 of thebase 511.

In addition, a flange 540 on the end of the lid 530 opposite from thehinge 532 is of size to fit over the top of the front wall 520, andcarries a latch dog 542 that will fit into a latch receptacle 544 in thetop side of the front wall, as shown in FIG. 10.

The rear portion of the lid 530, adjacent the frangible hinge 532 has aprojecting guide finger 546 that is curved and configured to fit intothe opening 526 in the rear wall 518 as the lid is closed, as will befurther shown. The lid 530 also has guide projections or lugs 548 at therear edge, that will fit into openings 550 formed on a flange on theupper edge of the rear wall 518 to maintain the lid in position when itis initially closed, and also when it is subsequently closed afterhaving been removed. The lugs 548 keep the lid 530 from sliding forwardonce the hinge 532 is fractured. There are guide projections or lugs 549formed on the lid corners near the hinge 532 that will pass to theinterior of the rear wall 518, as shown in FIG. 13. These guideprojections or lugs 549 keep the lid 530 from sliding backward. The lugs548 and 549, in conjunction, also insure that the lid 530 will staysquare with the base 511 during closure, and as the latch dog 542 entersthe opening 544 and latches under a suitable shoulder surface 544A onthe front wall 520 below the opening 544.

The frangible hinge 532 is separated into four width segments,interrupted by the openings or apertures 550 and an aperture 553 by thecenter guide finger 546. The frangible hinge 532 includes a thin section533 of molded plastic, and for example it could be in the range of 0.014inches thick, and the hinge also includes a flange 556 extending outwardfrom the rear wall 518 of the base and a flange portion 558 on theadjacent edge of the lid that is in line with and joins the flange 536around the perimeter of the lid.

The front wall 520 has a front panel 560 integrally molded with theupper edge of the front wall and inclined relative to the upright wall.The panel 560 is supported with suitable gussets 562 extending back tothe front wall 520. The upwardly facing surface 564 of the panel 560 ismolded smooth, so that it can be used for printing on the surface toidentify the specimen or tissue sample that is contained in thecompartment 522 of the base 511.

It can be seen that the flange 556 (See e.g., FIGS. 11-13) extendsrearwardly from the rear wall 518, and has a surface portion 566 thatslopes downwardly from the plane defined by the upper edges of the sideand end walls of the base 511. The upper wall edges define a plane andare indicated at 567 in FIGS. 11 and 12.

As shown in FIGS. 11, 12 and 13, as the lid 530 is hinged from theposition shown in FIG. 10 to a closed position during its first closing,the hinge 532 will fold as shown in FIG. 11, and the guide finger orprojection 546 will pass into the space defined by the U-shaped wall524, as shown in FIGS. 11 and 12. When the lid 530 reaches its positionas shown in FIG. 12 as it is closed, it can be seen that a portion 536Aof surface 536 on the underside of the flange at the rear or hinge endof the lid will come to rest on the surface 566, and that the surface536A is inclined so that when it comes to rest on surface 566 the lid530 is not fully closed, and the hinge 532 is still intact.

During the closing process, as also shown in FIG. 13, which is asectional view at a different location from FIGS. 11 and 12, the lugs548 on the lid 530 will slide to a position where they are to theexterior of the rear wall 518, and will prevent the lid 530 from slidingforwardly as it is closed. The lugs 549 will prevent the lid 530 fromsliding rearwardly. Also, for side to side guiding, there are lugs 570at opposite corners of the lid adjacent the latching end, or front end,and these will fit within the space between the side walls 516 to keepthe cover oriented relative to the base during closure and as the frontlatch dog 542 moves to a latched position.

As the lid 530 is moved between the positions shown in FIGS. 13 and 14,the flange portion 558 will rock or pivot on the upper surface 566 ofthe protrusions 556 on the base, and the surfaces are configured tocreate a tension force in the thin section 533 of the hinge 532 as theflanges 556 and 558 move apart as the lid is closed. When the lid 530 iscompletely closed as shown in FIG. 14, the frangible hinge 532 hasruptured under tension loads because of the configuration of the matingsurfaces 566 and 536A that spaces the ends of the flanges 556 and 558joined to frangible hinge 532 a greater distance than the length of themolded, thin hinge material 533 between the wall and lid edges. The lidis thus positively physically separated from the base 511 and is nolonger connected to the base by a hinge. The lid 530 is, however, heldby the guide finger 546 sliding along a curved surface defining theopening 526 in the rear wall 518, as also shown in FIG. 14.

It should be noted that the tension force put on the frangible hinge 532can be large and controlled because of the leverage that is generated bythe contact of the junction line 574 at the edge of surface 536A thatforms a fulcrum to cause the outer edge of the lid to move verticallyrelative to the base as the lid closing motion continues from theposition in FIG. 12 to the position of the lid in FIG. 14. The outer endof the flange 558 portion is lifted relative to the flange 556 and thetension force in the hinge as it is stretched is sufficient to rupturethe hinge section 533. The distance between the outer tip of the flangeportion 558, which is shown at 580 in FIG. 14, and the outer tip of theprotrusion 556, shown at 582, is greater than the length of the hingesection 533 so that the positive tension force will cause a rupturereliably and without any likelihood of having the hinge not separatecompletely when the lid is initially closed to its position shown inFIG. 14.

The latch dog 542 has a surface 542A that will fit under a shoulder 544Aon the front wall 520, just below the opening 544, after the latch doghas been passed through the opening 544 in the ledge at the upper edgeof the front wall 520.

The unitary molded cassette can be used for mounting tissue samples, andhas a lid that can be integrally molded with the base, through a hingethat will reliably rupture when the lid is moved to its first closedposition. Removing the lid from the base as a separate unit after theinitial closure merely requires unlatching the latch dog from under theledge of the front wall, and then lifting the lid as guided by the guidefinger 546 and the surfaces of the opening 526.

The lid can easily be replaced again by placing the lid rear portion sothat the guide finger 546 passes into the recess formed by the wall 524,and then through the opening 526, as it is pivoted closed. The lugs 548,549 and 570 serve to position the lid 530 as it is closed.

In summary, one embodiment of the invention is a molded tissue cassettecomprising a base having a compartment for holding tissue samples and alid for covering the compartment that is initially unitarily molded toan upper edge of one wall of the base with a molded frangible hinge. Thelid is constructed so that the frangible hinge will be fractured undertension loading as the lid is first hinged to its position to cover andoverlie the compartment. The lid has a surface that rests on the uppersurface of the one wall of the base and forms a pivot as the lid isfirst closed to create a tension load in the frangible hinge to fractureor rupture the hinge in tension, and also has suitable molded guidescooperating with portions of the base to precisely guide the lid intothe closed position. The guides and a latch dog will precisely hold thelid in position after it has been removed from the base as a separatepart and is replaced after the hinge is fractured.

Cassette 600

A histological tissue carrying cassette 600 in accordance with anotherembodiment of the invention can be described with reference to FIGS.15-19. As shown, cassette 600 includes a bottom wall 612 that has anumber of openings 614 formed therein, which provide for drainage. Thebottom wall 612 is surrounded by four upright side walls, when therectangular configuration is utilized, including a pair of side walls616, a rear end wall 618, and a front end wall 620. The four uprightwalls are secured to, and molded integrally with the bottom wall 612from a suitable plastic.

A compartment 622 is formed in relation to a rear wall with a generalU-shaped wall 624. In the space defined by the size of the U-shaped wall624, there are openings 626. The rear wall also has horizontal ledges628 at the top edge defining a slot 630 between the ledges.

The front wall 620 has a molded front panel 634 attached and integrallymolded with an upper edge of the front wall 620. The panel 634 isinclined at substantially a 45° angle relative to the upright wall 620,and has an upper surface 636 on which printing to identify the tissuesample that would be held in the cassette is placed. The printing caninclude a bar code, and text that identifies the tissue sample as to itstype and source, and can include information relating to tests to beperformed, for example.

Panel 634 is a print-receptive panel on which information is placed, andin order to print satisfactorily, particularly with thermal printingheads, the surface 636 must be flat, as well as smooth. In order toaccomplish a flat, smooth surface 636 from a molded plastic cassettemade out of suitable plastic, without further finishing, the presentinvention optimizes the size and placement of the ribs relative to thethickness of the panel 634 to support the panel. As shown, panel 634 issupported with a plurality of ribs 640 that, as shown in FIG. 17, aresecured to the front surface of the front wall 620, and then alsosupports a rear surface of the print-receptive panel 634.

In prior cassettes, it has been found that as the plastic cools aftermolding, the panel will tend to bend and warp for a variety of reasons.In many cassettes the side walls are continued forwardly at the samethickness to support the printable panel at the ends of the panel, andthus at least these end supports are relatively thick.

When combined with thinner support ribs between the side walls, theprint-receptive panel is supported by walls of varying thickness.Because walls of different thickness shrink different amounts whencooling after molding, the print-receptive panel will be necessarilypulled out of flat. Also, where a wall of substantially the samethickness as the print-receptive panel joins the panel at its end, thusforming an “L”, cooling after molding tends to pull the walls towardeach other, thus also tending to pull the panel out of flat.

Some prior cassettes also have ribs that are too thick relative to thethickness of the print-receptive panel. In these cassettes, the extraplastic present behind the print-receptive panel at the locations of theribs causes the plastic to sink, or indent, in these areas duringcooling after molding.

Typically, prior cassettes also do not have enough ribs to adequatelysupport the print-receptive panel for thermal printing. Many only havetwo ribs and others do not have any. When the print head moves acrossthese inadequately supported print-receptive panels, the pressure neededfor good-quality printing cannot be generated, even if the printreceptive panel is flat prior to printing.

No known prior cassettes have a sufficient number of closely spaced ribsof substantially equal thickness for satisfactorily supporting theprint-receptive panel for thermal printing.

The present invention involves a structure in which the ribs 640 are aselected thickness relative to the thickness of the print-receptivepanel 634, and a plurality of more than two are spaced across the entirewidth of the cassette, which is the length of the panel, and atlocations that provide adequate support. This will yield a flat, smooth,and printable surface 636 on the panel 634.

The cassettes 600 generally, for standard uses, run approximately 1.1inches in width, that is along the length of the panel 634. The ribs 640have a thickness that is in the range of 32% to 59% of the thickness ofthe front panel 620. Generally, ribs that are 60% or less in thicknessdo not generate indents on the adjoining wall. In this case, the frontpanel, as shown by the double arrows 644 in FIG. 18, has a thickness of0.04 inches, and the thickness of the ribs or gussets, as shown bydouble arrows 646 in FIG. 19 range between 0.013 and 0.024 inches. Thedifference in thickness of the ribs is due to draft, which is necessaryto allow the cassette to be ejected easily from the mold.

For adequate support of the front panel, a spacing of 0.2 inches betweencenter lines of the ribs 640 has been found to be satisfactory with thethicknesses provided and with a cassette width of 1.1 inches.

Using ribs that are substantially equal in thickness, carefullyselecting the ratio of the thickness of the ribs to the thickness of theprint-receptive panel, and providing a plurality of closely spaced ribssufficient in number to rigidly support the print receptive panelprovides a surface 636 on the print-receptive panel 634 that will beflat and smooth enough for printing without further machining orfinishing after molding and cooling.

A lid or cover (not shown) is placed over the top of the cassette afterthe tissue sample has been put in place.

The plastic molded cassette, as disclosed therefore provides for a lowcost cassette that can be used for containing tissue samples and whichcan be printed upon using thermal printing technology for identificationpurposes without further manufacturing procedures.

In summary, one embodiment of the invention is a molded tissue cassettecomprising a cavity formed by four upright walls around a perforatedbottom wall. One of the four walls has an integral moldedprint-receptive panel that is connected to the top edge of the one walland is inclined outwardly and downwardly and is spaced from the uprightadjacent wall.

The panel provides an upwardly facing surface for printing informationabout the tissue sample contained in the cassette. The information isreadily readable by automated equipment, as well as being visible to aperson looking at stacks of the cassettes in storage, for example.

The print-receptive panel is supported relative to the adjacent uprightwall with a plurality of molded ribs or gussets that are spaced alongthe length of the panel. The ribs or gussets are all substantially thesame thickness, and the thickness of the ribs or gussets selected issuch that upon cooling they do not cause uneven shrinkage that leavesindents on the outer surface of the panel directly opposite the ribs orgussets. The number and spacing of the ribs or gussets is selected toinsure that the panel does not warp along its length when cooling or insubsequent use.

Using only substantially equal thickness ribs or gussets to support theprint-receptive panel, properly selecting the thickness of the ribs orgussets in relation to the thickness of the print-receptive panel beingsupported, and providing a plurality of the ribs or gussets sufficientto support the panel for thermal printing, insures that after cooling ofthe molded plastic, a flat and smooth panel surface for printing isprovided without subsequent processing, such as grinding, polishing orsanding. Since ribs or gussets of differing thickness will shrinkdifferent amounts in the molding process, they must be substantially thesame thickness to achieve a flat print-receptive panel. Also, ribs orgussets that are too thick relative to the print-receptive panel thatthey support will cause indents in the panel directly opposite the ribsor gussets due to uneven cooling and therefore uneven shrinkage.

Although cassette 600 is described as a separate embodiment fromcassette 500, features of these two cassette embodiments are combined inother embodiments of the invention. For example, the print panel andsupport gussets of the cassette 600 are incorporated into the cassette500 in other embodiments of the invention. Similarly, the lid andfrangible hinge of the cassette 500 can be incorporated into thecassette 600. Other variations will also be apparent to those skilled inthe art. For example, although described as unitary molded members,other embodiments of the cassettes can be assembled from separatelymanufactured components.

Color Cassette Printer 200

A color cassette printer 200 in accordance with another embodiment ofthe invention can be described in connection with FIGS. 20-53. As shownin FIG. 20, cassette printer 200 has an enclosure 202 that includes abase 204, an access lid 206 on the top of a front end of the enclosureand a cover 208 on the top of a back end of the enclosure. An opening210 in the cover 208 receives a hopper 212 and cassette loading rod 214.Specimen cassettes such as cassettes 500 and 600 and variationsdescribed above (not shown in FIG. 20) are fed into the printer 200through the hopper 212 and loading rod 214. Cassettes with color printedspecimen information are outputted from the printer 200 at a slide 216.As shown, an operator control panel 218 is also located on the front endof the printer 200. Cassette printer 200 can be used to printinformation on any of a wide variety of cassettes including, but notlimited to those described herein.

The operation of cassette printer 200 can be briefly described inconnection with FIGS. 20-24. Lid 206 is pivotally mounted to theenclosure 202, and as shown in FIG. 21 includes a printhead assembly 220having a thermal printhead 222 mounted to its interior side. Lid 206 canbe raised to provide access to a cassette index assembly 224 and a colorprint ribbon receiving structure 226 within the enclosure 202 as shownin FIG. 22 (the lid is not shown in FIG. 22). When the lid 206 is in theclosed position, the printhead 222 is positioned at a printing positionwith respect to the cassette index assembly 224. During a printingoperation the cassette index assembly 224 picks a cassette from theloading rod 214 and drives the cassette in a reciprocal manner along aprinting path with respect to the printhead 222. The printhead 222transfers multiple colors of ink from an ink ribbon 418 and printsspecimen information in color on the cassette print zones. When theprinting operation is completed the index assembly 224 outputs theprinted cassette from the printer 200 by pushing the cassette to theoutput slide 216.

Lid 206 and printhead assembly 220 can be described in greater detailwith reference to FIGS. 21 and 23-24. As shown, the lid 206 includes atop panel 228 and a front panel 230 supported by a main frame 231 formedby brackets 232. A shaft 234 extending between the brackets 232pivotally mounts the lid 206 to the enclosure 202. Latch members 235 onthe ends of the brackets 232 releasably engage the enclosure 202 to holdthe lid closed 206 with the printhead assembly 220 positioned at theprint position with respect to the cassette index assembly 224. Theprinthead assembly 220 includes a subframe 221 formed by a pair ofbrackets 236, each of which is pivotally mounted to one of the mainframe brackets 232 by a pivot mount 238. The subframe brackets 236 havetabs 240 that extend through slots 241 in the main frame brackets 232 tolimit the range of motion of the printhead assembly 220 with respect tothe lid 206, and thereby also limit the range of motion of the printhead222 with respect to the cassette index assembly 224. The position of theprinthead 222 is generally fixed with respect to the cassette indexassembly 224 in the printer 200 during printing operations. However, inthe illustrated embodiment of the printer 200 the configuration of thesubframe brackets 236 on the main frame brackets 232 enables theprinthead to move over a relatively short distance (e.g., about 0.040inches in one embodiment) to accommodate manufacturing tolerances and toenable a controlled printhead force to be applied between the printheadand cassettes during the printing operations as described below.

Crossbar 242 extends between and is mounted to the subframe brackets236. Printhead pivot plate 244, which includes a base 260 and spacedapart tabs 262, is mounted to the crossbar 242 by a y-axis pivotmechanism 246 that allows the pivot plate and components described belowincluding the printhead 222 mounted to the pivot plate to rotate withrespect to the cassette index assembly 224 about a y-axis that isparallel to the printing path. The y-axis pivot mechanism enables theprinthead 222 to accommodate variations in the planar position of theprint zone of the cassettes and remain flat and parallel to the printzones during printing operations. In the embodiment shown the y-axispivot mechanism 246 includes a y-axis pivot pin 248 that extends throughthe crossbar 242, a pin capture plate 250 and a screw 252. Other y-axispivot mechanisms can be used in other embodiments of the invention (notshown). Mounted to the main frame brackets 232 and positioned above theprinthead assembly 220 is a hood 254. A print force bias member, whichis a spring 256 in the illustrated embodiment, is positioned in acompressed state in a recess 258 of the crossbar 242, between thecrossbar and the hood 254. The print force bias spring 258 therebyapplies a printhead force that urges the printhead assembly 220 andprinthead 222 in a generally downward or z-direction toward the cassetteindex assembly 224 with respect to the hood 254 and lid 206. Oneembodiment of the invention uses a printhead force of about 1.3 lbs, butthis force can vary depending on a range of factors such as the size ofthe printhead (which is e.g., 14 mm in one embodiment of the invention).Other embodiments of the invention (not shown) include other approachesfor generating the printhead force during printing operations.

Printhead mount bar 264 is mounted between the tabs 262 of printheadpivot plate 244 for rotational movement about an x-axis by pivot pins266. An x-axis adjustment mechanism including an x-axis bias member,which is a spring 268 in the illustrated embodiment, and an adjustmentscrew 270, adjustably fixes the position of the printhead mount bar 264about its rotational axis. As shown, the x-axis bias spring ispositioned in a compressed state in a recess 272 of the printhead mountbar 264, between the printhead mount bar and the base 260 of theprinthead pivot plate 244. The printhead 222 is mounted directly to aprinthead mount plate 274 (e.g., by screw 276). The printhead mountplate 274 is mounted to and supported from the printhead mount bar 264by a pair of standoff mounts 278 that extend between the printhead mountbar and the printhead mount plate on opposite sides of the printhead222. By rotating the adjustment screw 270, the printhead 222 can berotated and positioned about an x-axis to adjustably fix the printheadheater line (not visible) at an optimized printing position. Otherembodiments of the invention (not shown) have other x-axis adjustmentmechanisms, or no x-axis adjustment mechanism if adjustment of theprinthead heater position is not needed. Still other embodiments of theinvention (not shown) include other structures for mounting theprinthead 222. For example, the printhead 222 can be mounted moredirectly to the pivot plate 244.

A cross member 284 extends between and is mounted to the main framebrackets 232 at a location opposite the printhead 222 from the printheadmount bar 264. Ribbon deflector 286 is mounted to the cross member 284adjacent to the printhead 222, and has a curved lower edge 288 toposition the print ribbon 418 as it passes the printhead. A pair ofribbon guide rollers 290 and 292 also extend between and are rotatablymounted to the main frame brackets 232. Ribbon rollers 290 and 292 guidethe print ribbon 418 on the side of the printhead 222 opposite theribbon deflector 286.

A circuit board 294 having a connector 296 is mounted to the lid 206with the connector located directly above (in the z-direction) theprinthead 222. The electrical cable 298 extending from the printhead 222is connected to the connector 296. The electrical cable is configured tohave one or more loops 300 (one is shown in the illustrated embodiment)between the connector 296 and printhead 222. Because the cable 298extends substantially only in the z-direction above the printhead 222and has loop 300, the force exerted by the cable on the printheadassembly 220 is relatively low and generally centered on the rotationaly-axis of the printhead so as to minimize interference with theprinthead assembly.

A cross member 302 extends between and is mounted to the subframebrackets 236 at a location between the ribbon rollers 290 and 292. Acircuit board 304 is mounted to the cross member 302 and has an opticalsensor 306 mounted thereto. Optical sensor 306 is located to detectlight emitted by LEDs 429 (shown, e.g., in FIG. 43) and transmittedthrough the print ribbon 418. As described in greater detail below, thedetected light signals produced by sensor 306 are used by the printercontrol system 434 to track the color panels on the print ribbon 418 andto detect the end of the print ribbon.

Hopper 212 and the manner by which it is releasably mounted to theprinter 200 can be described with reference to FIGS. 25-28. As shown,the hopper 212 is a tubular member formed from a pair of spaced-apartU-shaped members 308 secured together on one side by brackets 309 toprovide elongated slots 310 and 311 on the front and back sides,respectively. The hopper 212 has a cross sectional shape that receivesthe cassettes in the configuration of the cassettes when loaded on theloading rod 214 (e.g., with the cassette lid open and the lid andcassette base generally flat or planar as shown in FIG. 28). Asdescribed in greater detail below, the slot 311 on the back side of thehopper 212 functions as a structure for releasably receiving andengaging the cassette loading rod 214. The bottom of the hopper 212 hasan opening 312 on the front side. The hopper 212 extends through theopening 210 in the cover 208 and is releasably engaged to structureswithin the enclosure 204 with the bottom end and opening 312 locatedadjacent to the cassette index assembly 224.

In the illustrated embodiment, a releasable latch structure includes oneor more first members such as pins 314 on the bottom of the hopper 212(four are shown in the illustrated embodiment) and one or more secondmembers such as pin-receiving latches 316A and 316B that are mounted tobracket 318 in the enclosure base 204. Pins 314 cooperate with latches316 to securely retain the hopper 212 in position in the printer 200,yet to allow the hopper to be inserted into and removed from the printerby hand without the use of tools.

As perhaps best shown in FIGS. 27 and 40, latches 316A and 316B eachhave a pair of pinching fingers 317 joined together at neck ends 319Aand 319B. The pairs of fingers 317 are separated by slots 321 havingexpanded pin receiving openings 323. The open ends of the slots 321 alsohave tapered guide openings 325 that extend into the pin receivingopenings 323. In one embodiment, each pair of latches 316A and 316B isformed as a one-piece plastic member with the neck ends 319 of each pairjoined to a mount plate 327. When the hopper 212 is inserted into theprinter 200, the fingers 317 will flex as the hopper pins 314 are guidedinto the openings 323 through guide openings 325. The compliant andresilient nature of the latches 316A and 316B cause the fingers 317 toengage the hopper pins 314 in the openings 323. In one embodiment of theinvention, the neck ends 319B connecting fingers 317 of latches 316B arewider than the neck ends 319A connecting fingers 317 of latches 316A.Latches 316B are therefore less compliant, and can more accuratelylocate the end of the hopper 212 adjacent to the picker plate 398 thanthe end of the hopper engaged by latches 316A. The accuracy androbustness of the cassette picking operations (described below) isthereby enhanced.

As perhaps best shown in FIG. 26, an electrical contact 320 is mountedon the back side near the bottom of hopper 212, and as discussed belowis configured for electrical coupling to a memory chip 348 on thecassette loading rod 214. Other embodiments of the hopper 212 (notshown) do not include structure for engaging the cassette loading rod.Still other embodiments of the printer 200 (not shown) do not include ahopper 212, or the hopper is fixedly mounted to the printer.

Loading rod 214 and the manner by which it is releasably mounted to theprinter 200 can be described with reference to FIGS. 28-33. As shown,the loading rod 214 is an elongated member having a cassette engagingstructure in the form of a T-shaped member 322 extending along thelength of its front side, a hopper engaging structure in the form of aT-shaped member 324 extending along the length of its back side, acassette retaining structure 326 on a printer end, and a rod retainingstructure 328 on the printer end. The T-shaped member 322 provides apair of slots 330 that extend along the length of the loading rod 214.The T-shaped member 322 and slots 330 are configured to engage the feedstructures on the cassettes and generally constrain movement of thecassettes in a transverse direction with respect to loading rod 214, andto allow a plurality of stacked cassettes to slide long the length ofthe rod to the cassette retaining structure 326. Similarly, the T-shapedmember 324 provides a pair of slots 332 that extend along the length ofthe loading rod. The loading rod slots 332 are configured to engage theportions of the hopper U-shaped members 308 on opposite sides of thehopper slot 311, enabling the loading rod 214 and cassettes thereon tobe slid into the hopper 212, yet be generally constrained from movementin a direction transverse to the hopper. Other embodiments of theloading rod (not shown) do not include a hopper engaging structure. Theillustrated embodiment of loading rod 214 includes a memory chip 348.The memory chip 348 is mounted to the loading rod 214 at a position thatwill enable the memory chip to electrically contact or otherwise becoupled for data transfer with the electrical contact 320 on the hopper212 when the loading rod is inserted into the printer 200. Otherembodiments of the loading rod (not shown) have other cassette engagingstructures and/or no hopper engaging structure.

The cassette retaining structure 326 includes a resilient tab 334 havinga tooth 336 and an actuation finger 338. When the tab 334 is in itsunbiased or neutral position shown in FIGS. 29 and 32, the tooth 336extends into the slots 330 and under the end-most cassette on theloading rod 214, and prevents the cassettes from sliding off the printerend of the loading rod. Finger 338 functions as a release member. Whenthe loading rod 214 is fully inserted into the printer 200 as shown inFIG. 33, the finger 338 engages a tab 340, and deflects the tab 334 in adirection that retracts the tooth 336 from under the cassettes, allowingthe cassettes to slide off the loading rod 214 and onto the cassetteindex assembly 224. Other embodiments of the loading rod 214 includeother cassette retaining structures (not shown), such as for example atab 334 that is not resilient, and/or an active mechanism for enablingthe removal of cassettes from the rod. In yet another embodiment of theinvention (not shown), the tab of the cassette retaining structureincludes a more flexible hinge, and brackets extend generallytransversely from the tab at locations above and below the hinge. Aspring is mounted between the brackets to bias the tooth to the cassetteretain position at which it extends under the end-most cassette on theloading rod. When this embodiment of the loading rod is inserted intothe printer, the finger deflects the tab and tooth against the biasforce of the spring.

The rod retaining structure 328 includes a resilient tab 342 and atapered engaging member 344. When the tab 342 is in its unbiased orneutral position shown in FIG. 32, the member 344 is positioned so thatit will engage a bracket 346. As the loading rod 214 is inserted intothe printer 200, the member 344 engages the bracket 346 and is deflectedwith the tab 342. When the loading rod 214 is fully inserted into theprinter as shown in FIG. 33, the resilient nature of the tab 342 urgesthe tab toward its neutral state and causes the member 344 to engage thebracket 346. The rod retaining structure 328 thereby securely retainsthe loading rod 214 within the printer 200, yet allows the loading rodto be inserted into and removed from the printer by hand without the useof tools. The rod retaining structure 328 also provides a downward(toward the printer) force that causes the deflection of tab 334 and therelease of the cassettes on the loading rod 214. Other embodiments ofthe loading rod (not shown) include a different or no rod retainingstructure.

Cassette index assembly 224 and aspects of its operation can bedescribed with reference to FIGS. 22, 27 and 34-38. As shown, the indexassembly 224 includes a carriage support 350, a carriage drive 352, acarriage 354 and a picking mechanism 356. Carriage support 350 includesa pair of spaced apart and generally horizontally oriented rods 358extending between and mounted to brackets such as 360. The rods 358 arepositioned to define a support surface that extends at an angle withrespect to the y-axis and to support the cassettes at an angle that willposition the print panels of the cassettes in the proper printingorientation with respect to the printhead 222 as the cassettes aredriven along the printing path past the printhead. In the illustratedembodiment, rods 358 are positioned to define a support surface at anangle of about 45° with respect to printing path, to locate the printpanels of the cassettes in a generally horizontal plane corresponding tothe horizontally oriented printhead 222 described above (e.g., as shownin FIGS. 21 and 24). Carriage 354 includes a cassette carrier 362mounted to the rods 358 for reciprocal motion along the printing paththat extends in the y-direction. The carrier 362 includes a push bar 370and a support shelf 364 having a print area 366, reset area 368 and tab372. Support shelf 364 is a generally elongated member that supports theback walls of the cassettes when the bases of the cassettes are restingon the rods 358. The reset area 368 of the shelf 364 is displaceddownwardly in a vertical direction from the print area 366, and istherefore also spaced from the printhead 222 by a greater distance thanthe print area 366. The vertical distance between the reset area 368 andthe print area 366 is also greater than the range of movement of theprinthead 222 in the z-direction allowed by the subframe brackets 236and tabs 240. A sloping transition area 374 joins the print area 366 andthe rest area 368 of the shelf 364. An eject finger 410 extendsforwardly (i.e. in a downstream direction) from the carrier 362.

Carriage drive 352 includes a stepper motor 376 that is coupled by adrive linkage including gears 388 and 390 to a first pulley (not shown)on a first or input end of the index assembly 224, upstream from theprinthead 222. A second pulley 392 is located on a second or output endof the index assembly 224, downstream from the printhead 224. A drivebelt 394 extends around pulley 392 and the first pulley, and is coupledto the carriage 354. Motor 376 can thereby drive the carriage 354 on thecarriage support 350 in a reciprocal manner along the print path.

Picking mechanism 356 includes a carriage 396 that is mounted to rods358 for reciprocal motion and a picker plate 398 mounted to the carriage396. A biasing member such as a spring 359 that extends between tab 361on the picker mechanism carriage 396 and tab 363 on the carriage support350 biases the picking mechanism carriage 396 in the first directiontoward the output end of the carriage assembly 224. The carriage 396 isdriven in the second direction against the bias force of the spring bythe carriage 354 as described in greater detail below.

Reset bracket 400 overlays the rods 358 at a reset location that isupstream from the printhead 222. As shown, the reset bracket 400includes a cassette engaging member 402 having deflection wings 404 onits opposite sides. An end 406 of the member 402 is pivotally mounted tothe cassette index assembly 224 so as to enable the cassette engagingmember 402 to move in a direction generally perpendicular to the supportsurface defined by the rods 358. The wings 404 on the reset bracket 400cause the bracket to deflect upwardly, away from the rods 358, whenengaged by a cassette. Motion of the reset bracket 400 is sensed by areset bracket sensor 408. As described in greater detail below, thereset bracket 400 releasably engages cassettes during reset strokes ofthe index assembly 224, and causes the cassettes to move between thereset area 368 and the print area 366 of the carrier 362. Sensor 408senses the presence of cassettes engaged by the reset bracket, andprovides signals representative of the sensed cassettes to the controlsystem 434 described in greater detail below.

A thermal print ribbon assembly 412 that can be used with printer 200can be described with reference to FIG. 42. As shown, the print ribbonassembly 412 includes supply spool 414, take-up spool 416, andmulti-color thermal ink ribbon 418. The composition of thermal inkribbons such as 418 is generally known. In one embodiment of theinvention the ribbon 418 has a plurality of primary color ink blocks(e.g., yellow, magenta and cyan) and black ink blocks (not separatelyshown in FIG. 42) spaced in repeating sequences along its length.Rotatably mounted to the take-up spool 414 is a hub 420. A print ribbonmemory chip 422 is mounted to the hub 420.

The print ribbon receiving structure 226 for receiving and driving theprint ribbon assembly 412 can be described with reference to FIGS.39-43. As shown, the print ribbon receiving structure 226 includes apair of supply spool mounts 424 rotatably supported toward the back ofthe printer 200 and a pair of take-up spool mounts 426 rotatablysupported toward the front of the printer. One of both the supply spoolmounts 424 and the take-up spool mounts 426 are driven by ribbon drivemotors 428 (shown e.g., in FIG. 44) mounted in the enclosure base 204.One of the supply spool mounts 424 includes an electrical contact 430configured for electrical coupling to the memory chip 422 on the supplyspool 414. The print ribbon assembly 412 is loaded onto the print ribbonreceiving structure 226 by mounting the supply spool 414 to the supplyspool mounts 424, and mounting the take-up spool 416 to the take-upspool mounts 426. The memory chip 422 on the supply spool 414 iselectrically coupled to the ribbon supply chip contact 430 when thesupply spool is mounted to the supply spool mounts 424. A bracket 427supporting a pair of ribbon sensor LEDs 429 is mounted to the carriageindex assembly 224 (shown, e.g., in FIG. 27). As shown in FIG. 24, afterthe print ribbon assembly 412 is mounted to the print ribbon receivingstructure 226 and the lid 206 is closed, the print ribbon 418 is guidedbetween the supply spool 414 and take-up spool 416, and past theprinthead 222, by rollers 290 and 292 and ribbon deflector 288, andpasses between the LEDs 429 and the ribbon sensor 306.

The electrical subsystem 432 for printer 200 is illustrated in FIG. 44.As shown, the electrical subsystem 432 includes a microprocessor-basedcontrol system 434 that is coupled to external devices such as acomputer (not shown) through an interface port 436. The control system434 is also coupled to ribbon sensor 306, printhead 222, control panel218, tray sensor 438, ribbon drive motors 428, ribbon supply chipcontact 430, loading rod chip contact 320, input sensor 441 and resetbracket sensor 408. In one embodiment of the invention, the specimendata is generated on a system such as a PC (not shown). The operatorinterface and software used to configure the specimen data for printjobs is run on the PC in this embodiment, and the specimen data isreceived by printer 200 through the interface port 436. For example, thespecimen data received at interface port 436 can include color datarepresentative of colors that identify specimen information such as, forexample, the type of tissue in the cassette or the tissue source (e.g.,clinic location), and the colors that the fields (e.g., color bar, textand bar code) are to be printed. In another embodiment of the inventionthe control system 434 is programmed to select the colors that thefields are to be printed based on the information received through theinterface port (e.g., the control system selects the color yellow basedon the knowledge that the tissue is a liver biopsy sample). Otherportions of the control system 434 then receive this generated specimendata and control the printer accordingly.

The operation of printer 200 can be described generally with referenceto FIGS. 20-44. During setup, the hopper 212 is latched into theenclosure 202 and a loading rod 214 containing a supply of unprintedcassettes is loaded into the hopper and latched into the printer in themanner described above. When the loading rod 214 is inserted, alower-most cassette on loading rod slides off of the rod onto a stagingarea 440 (shown e.g., in FIG. 33). The presence of a cassette on thestaging area 440 is detected by the input sensor 441 that is coupled tothe control system 434. If no cassette is detected on the staging area440 (e.g., the supply of cassettes is exhausted or the cassettes arejammed on the loading rod 214), control system 434 can respondaccordingly (e.g., by providing a responsive display and discontinuingprinting operations). In the illustrated embodiment of printer 200, thecassettes are held in a generally horizontal orientation on the stagingarea 440. Lid 206 is opened during setup to present access to the printribbon receiving structure 226. After the print ribbon assembly 412 ismounted to the print ribbon receiving structure 226 the lid 206 isclosed to locate the print ribbon 418 at the printing position withrespect to the printhead 222 in the manner described above. As discussedabove, the printer 200 is also connected to a computer or other device(not shown) through the interface port 436 to receive cassette print jobinformation including data representative of the specimen information tobe printed on the cassettes during print operations.

Printer 200 is turned on by actuating an ON/OFF switch on the controlpanel 218. When switched ON, the control system 434 accesses informationon the loading rod memory chip 348 through electrical contact 320, andaccesses information on the ribbon supply memory chip 422 through theelectrical contact 430. Information stored on the loading rod memorychip 348 can include, for example, one or more of cassette type and thenumber of cassettes remaining on the loading rod 214. Similarly,information stored on the ribbon supply memory chip 422 can includeribbon type, the number of images remaining on the ribbon 418, theproduction date and batch no. Other or additional types of informationcan be stored on memory chips 348 and 418. Information on the memorychips 348 and 418 is used to control the operation of printer 200, andcan be updated after print operations. For example, if the informationon memory chips 348 or 418 indicates that the supply of cassettes orribbon is exhausted, the control system 434 will not execute a requestedprint operation. Information stored on memory chips 348 and 422representative of the number of remaining cassettes and the number ofimages remaining on the ribbon 418 can be updated following each printoperation.

In one embodiment of the invention, the carriage 354 is moved to a fullyretracted or home position when the printer is turned on. By this actionthe carriage 354 urges the picking mechanism 356 to a retracted positionagainst the bias force of spring 359 with the picker plate 398 locatedbehind the cassette on the staging area 440 (shown e.g., in FIG. 33).Print operations are initiated upon the receipt of print job requests.The motor 376 then drives the carriage 354 to the picked position shownin FIG. 34. This movement of the carriage 354 releases the pickingmechanism carriage 396 from its retracted position and causes the pickerplate 398 to move through a picking stroke during which the picker platepushes the cassette on the staging area 440 off the staging area and inthe first direction toward the carrier 362 of the cassette indexassembly 224. This picking stroke causes the base of the cassette tofall under the force of gravity onto the print area 366 of the shelf364, with the bottom wall of the base resting on the support surfaceformed by the rods 358 and the back wall of the base resting on theshelf (shown e.g., in FIG. 34). The print zone on the cassette isthereby positioned to pass by the printhead 222 during the printoperation at a printing position (i.e., with the print zone at aposition with respect to the printhead that enables printing onto theprint zone). Another cassette will slide off the loading rod 214 anddrop onto the picker plate 398 during the picking stroke. During theremaining portions of the print operation described below, the pickingmechanism 356 remains in the picked position with the picker plate 398supporting a cassette above the staging area 440.

After picking, the cassette carriage 354 is driven from the pickedposition through a printing stroke. During the printing stroke the pushbar 370 pushes the cassette in the first or downstream direction, whilethe cassette is located on the print area 366 of the shelf 364, past thereset bracket 400 and past the printhead 222 to a print stroke endposition (shown e.g., in FIG. 35). As the cassette is driven past thereset bracket 400 the deflection wings 404 cause the bracket to belifted up and to ride over the cassette, and thereby not interfere withthe motion of the cassette during the printing stroke. In connectionwith the printing stroke the control system 434 actuates the ribbondrive motors 428 to position an ink panel of the selected color of theprint ribbon 418 over the printhead 222 before the cassette is drivenpast the printhead. Signals received from ribbon sensor 306 are used bythe control system 434 to assure that the selected color panel of theink ribbon 418 is positioned over the printhead 222. During the printingstroke the control system 434 actuates the printhead 222 as a functionof the specimen data to heat and transfer ink from the print ribbon 418and to print the specimen information onto the print zone on thecassette.

The specimen information printed on the cassette can be the same as orsimilar to that printed by slide printer 10 and described above. Forexample, a color bar can be printed at a first location, a bar code canbe printed at a second location, and text can be printed at a thirdlocation. These information fields can be printed in any of a widevariety of colors using the ink available on the print ribbon 418. Forexample, the selected color(s) can be any one or more of the colors ofthe primary and black ink panels, or colors available from anycombination of the colors of the primary and black ink panels. Thecolors can, but need not be, selected to represent sample informationsuch as the tissue type or the source of the tissue. A bar code or otherinformation field intended for machine-reading can, for example, beprinted in black ink to maximize its contrast with the print zonebackground.

If the requested print operation includes multiple color printing (e.g.,a magenta color bar and/or magenta text and a black bar code, or a colorbar having a color formed by a combination of two or more primary and/orback colors), the control system 434 actuates the ribbon drive motors428 to position the appropriate color ink panel of the print ribbon 418adjacent to the printhead 222, and drives the carriage through a resetstroke and another printing stroke. During the reset stroke the carriage354 is driven in the second or upstream direction. As the carriage 354is driven in the second direction, the side wall of the cassette on thefront end near the print panel (i.e., the upstream side) will engage theback of the printhead 222 (i.e., the downstream end of the printhead)and stop the motion of the cassette with respect to the printhead. Withcontinued motion of the carriage 354 the cassette will then slide on theshelf 364 from the print area 366, across the transition area 374 andover the reset area 368. Because the reset area 368 is verticallydisplaced from the print area 366, the cassette will drop down onto thereset area of the shelf 364 under the force of gravity (shown e.g., inFIG. 36). Other embodiments of the invention (not shown) have otherstructures such as active mechanisms for moving cassettes from the printarea to the reset area. As described above, the printhead 222 andcarriage 354 are configured in such a manner that when the cassette ison the reset area 368, the cassette is below the printhead to space theprint zone of the cassette from the printing position, and provideclearance between the cassette print zone and the printhead during thereset strokes. With continued motion in the second direction during thereset stroke the carriage 354 causes the tab 372 on the shelf 364 toengage the cassette, and to drive the cassette in the second directionback under and past the printhead 222.

During this portion of the reset stroke the cassette will engage thedownstream deflection wing 404 on the reset bracket 400, and deflect thereset bracket upwardly over the cassette. At the end of this portion ofthe reset stroke the cassette is located under the reset bracket 400,with the reset bracket resting on the cassette and the cassette on thereset area 368 of the shelf and the push bar 370 spaced from theupstream side wall of the cassette. During a subsequent portion of thereset stroke the carriage 354 is again driven in the first direction.The force of the reset bracket 400 on the cassette is sufficient thatduring this motion of the carriage 354 the cassette will remainpositioned under the reset bracket, and slide from the reset area 368 upthe transition area 374 and onto the print area 366 (i.e., as shown inFIG. 37). A printing stroke of the type described above is then repeatedto print specimen information in the second color. The control system434 can actuate the ribbon drive motors 428 to advance the print ribbon418, and to drive the carriage 354 in reciprocal manner throughadditional reset and printing strokes, to print specimen information inthird or third and fourth colors if specified by the requested printoperation. Other embodiments of the invention (not shown) include othermechanisms for providing clearance by moving the cassettes around thegenerally fixed position printhead between different color printstrokes.

Following the completion of the final printing stroke the control system434 drives the carriage 354 through an eject stroke. During a firstportion of the eject stroke the carriage 354 is driven in the forwarddirection to such an extent that the printed cassette is pushed off ofthe rods 358. At this position the cassette rotates on the carriageshelf 364, and the base of the cassette drops onto the eject finger 410(shown e.g., in FIG. 22) and the lid of the cassette rises to a positiondownstream of a sideplate tab 365 (shown e.g., in FIG. 39). During asecond portion of the eject stroke the carriage is moved in the seconddirection to urge the upstream side wall of the cassette into engagementwith the carriage bracket 360, to urge the upstream side wall of the lidinto engagement with the sideplate tab 365, and to withdraw the ejectfinger 410 from under the cassette. The action of this portion of theeject stroke causes the base of the printed cassette to drop off of theeject finger 410 and onto a ledge 442 between the carriage 354 and theslide 216 (shown e.g., in FIG. 43), with the upstream end of thecassette base still resting on the carriage 354. The carriage 354 isthen driven in the forward direction through another portion of theeject stroke to engage the eject finger 410 with the upstream side wallof the printed cassette, and to push the cassette from the ledge 442over the slide 216. The printed cassette will then move down the slide216 and exit the printer 200. Control system 434 will discontinue printoperations if tray sensor 438 is actuated, indicating that the slide 216is full of printed cassettes. Following the completion of the ejectstroke the carriage 354 is driven back to its home position if anothercassette print job is pending. As the carriage 354 is driven back to itshome position it urges picking mechanism 356 back to its retractedposition which causes the picker plate 398 to be withdrawn from underthe next cassette, and causes the cassette to drop onto the staging area440.

An output tray 450 that can be included in some embodiments of theprinter 200 is illustrated in FIGS. 45-47. In the illustratedembodiment, the output tray 450 includes a base 452 that is mounted tothe base 204 of the enclosure 206 below the slide 216, and a stop 454 onthe end of the base 452. The base 452 is slidably mounted with respectto the slide 216, and is shown in the extended position in FIGS. 45-47.The base 452 can also be moved to a retracted position (not shown) withthe stop 454 located at the bottom of slide 216. The stop 454 can bemoved by an operator without the use of tools between an up positionshown in FIG. 46 and a down position shown in FIG. 47. When in the upposition the stop 454 will retain printed cassettes on the base 452and/or slide 216. When the stop 454 is in the down position cassetteswill be able to slide off of the base 452 and/or slide 216.

A pivotal latch structure that includes a shaft 456 on the stop 454 anda shaft receiving structure 458 on the base 452 can be described withreference to FIGS. 48-53. As shown, the shaft receiving structure 458includes one or more hooks 460 and one or more tongues 462 extendingfrom the distal end of the base 452 at transversely spaced positions.The illustrated embodiment includes a pair of hooks 460 and a singletongue 462 between the hooks. Other embodiments (not shown) can includeother arrangements of hooks 460 and tongues 462. The hooks 460 andtongue 462 define a rotational axis and are configured to receive theshaft 456 on the stop 454. The shaft 456 includes cylindrical sections464 that rotatably mate with the hooks 460 and flat surfaces 466 atlocations corresponding to the location of the tongue 462. When the stop454 is in the up position, the tongue 462 is engaged with one of theflat surfaces 466 to releasably retain or latch the stop in the upposition. Similarly, the tongue 462 can engage another of the flatsurfaces 466 to releasably latch the stop 452 in the down position.

Although the present invention has been described with reference topreferred embodiments, those skilled in the art will recognize thatchanges can be made without departing from the spirit and scope of theinvention. For example, some embodiments of the claimed invention can beimplemented in ink jet, laser or other printers in addition to thethermal printers described herein.

1. A histological specimen container printer, including: a specimen container receiving structure to receive histological specimen containers having a print zone; an ink receiving structure to receive a multi-colored ink source; a print head; a drive mechanism to drive specimen containers received by the container receiving structure with respect to the print head; and a control system responsive to specimen data representative of histological specimens to control the drive mechanism and the print head, including causing the print head to transfer multiple colors of ink from the ink source and print specimen information in color on the print zones of specimen containers, wherein the specimen data includes color data representative of a color that identifies specimen information, and the control system causes the print head to print the specimen information in color as a function of the color data.
 2. (canceled)
 3. The specimen container printer of claim 1 and further including a color selecting system to select the color data as a function of the specimen data that identifies the specimen information.
 4. The specimen container printer of claim 3 wherein the color selecting system selects the color data as a function of specimen data identifying tissue type.
 5. The specimen container printer of claim 1 wherein the control system causes the print head to print the specimen information in the form of color blocks.
 6. The specimen container printer of claim 1 wherein the control system causes the print head to print the specimen information in the form of bar codes.
 7. The specimen container printer of claim 1 wherein the control system causes the print head to print the specimen information in the form of text. 8.-13. (canceled)
 14. The specimen container printer of claim 1 wherein: the print head is a thermal print head; and the ink receiving structure is a thermal ink source receiving structure. 15.-17. (canceled)
 18. The specimen container printer of claim 1 wherein the specimen containers are slides.
 19. The specimen container printer of claim 1 wherein the specimen containers are cassettes.
 20. The specimen container printer of claim 1 wherein: the specimen container receiving structure includes a carrier-receiving structure to receive a carrier holding a plurality of specimen containers and having a memory device storing information about the specimen containers held by the carrier; the printer further includes a container carrier data port for data communication with the memory device on a carrier received by the carrier-receiving structure; and the control system is coupled to the carrier data port, receives container information from the memory device through the data port, further controls the printer as a function of the received container information, and provides updated container information to the data port for storage on the memory device.
 21. The specimen container printer of claim 20 wherein: the ink receiving structure receives an ink source having a memory device storing information about the ink source; the printer further includes an ink source data port for data communication with the memory device on an ink source received by the ink receiving structure; and the control system is coupled to the ink source data port, receives ink source information from the memory device through the data port, further controls the printer as a function of the received ink source information, and provides updated ink source information to the data port for storage on the memory device.
 22. The specimen container printer of claim 1 wherein: the ink receiving structure receives an ink source having a memory device storing information about the ink source; the printer further includes an ink source data port for data communication with the memory device on an ink source received by the ink receiving structure; and the control system is coupled to the ink source data port, receives ink source information from the memory device through the data port, further controls the printer as a function of the received ink source information, and provides updated ink source information to the data port for storage on the memory device.
 23. The specimen container printer of claim 1 wherein the control system causes the print head to transfer multiple colors of ink from the ink source and print color blocks representative of the specimen information at first locations on the print zones of the specimen containers.
 24. The specimen container printer of claim 23 wherein: the specimen data includes specimen type information; and the control system causes the print head to print color blocks in colors representative of the specimen types.
 25. The specimen container printer of claim 23 wherein the control system causes the print head to print bar codes representative of the specimen information at second locations on the print zones of the specimen containers, wherein the second locations are spaced from the first locations.
 26. (canceled)
 27. The specimen container printer of claim 25 wherein the control system causes the print head to print text representative of the specimen information at third locations on the print zones of the specimen containers, wherein the third locations are spaced from the first and second locations.
 28. (canceled)
 29. The specimen container printer of claim 24 wherein the control system causes the print head to print text representative of the specimen information at second locations on the print zones of the specimen containers, wherein the second locations are spaced from the first locations. 30.-49. (canceled)
 50. A method for operating a color printer to print specimen information on histological specimen containers, including actuating a color printer as a function of specimen data representative of specimen information to apply multiple colors of ink and print the specimen information in color on the print zones of the specimen containers, wherein the specimen data includes color data representative of colors that identify specimen information, and actuating the color printer includes printing the specimen information in color as a function of color data.
 51. (canceled)
 52. The method of claim 50 wherein actuating the color printer includes printing specimen information in the form of color bars as a function of the color data.
 53. The method of claim 52 wherein actuating the color printer includes printing specimen information in the form of bar codes.
 54. The method of claim 53 wherein actuating the color printer includes printing specimen information in the form of text.
 55. The method of claim 50 wherein actuating the color printer includes printing specimen information in the form of text.
 56. The method of claim 55 wherein printing the specimen information in the form of text includes printing text in color as a function of the color data.
 57. (canceled)
 58. The method of claim 50 wherein actuating the printer includes actuating a thermal print head to heat and transfer ink from a thermal print ribbon onto the specimen containers. 59.-71. (canceled) 